Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Octopamine- and dopamine-sensitive adenylate cyclases were studied in the brain of Locusta migratoria during its metamorphosis. In the adult brain the effects of octopamine and dopamine on adenylate cyclase were additive, suggesting the presence of separate populations of adenylate cyclase-linked receptors for octopamine and dopamine. There are no separate receptors for noradrenaline. Octopamine stimulates adenylate cyclase in both adult and larval brain; however, in adult brain octopamine is more potent than in larval brain. Dopamine stimulates adenylate cyclase activity only in adult brain. The sensitivity of adenylate cyclase to octopamine changes during the development of the animal. Phentolamine and cyproheptadine are potent antagonists of octopamine-stimulated adenylate cyclase, while propranolol has a weak effect. No cytosol factor which would modulate either basal or octopamine-stimulated adenylate cyclase was found. The effect of GTP and octopamine on adenylate cyclase was synergistic in adult brain but not in larval brain, while the effect of GppNHp and octopamine was synergistic in both adult and larval brains.
Cell Mol Neurobiol 1984 Sep
PMID:Octopamine- and dopamine-sensitive adenylate cyclase in the brain of Locusta migratoria during its development. 644 43

The levels of adenylate nucleotides were examined in the digestive gland and ovotestes of Biomphalaria glabrata during cercarial shedding of Schistosoma mansoni, 10 weeks post-infection. In general, parasitization resulted in decreases in the adenylate levels in both tissues, but the results were not statistically significant. Moreover, the energy charge ratio was not significantly altered. The mean energy charge in ovotestes from uninfected and infected individuals was 0.81 and 0.77, respectively, and that in the digestive gland, 0.70 and 0.66, respectively. Extensive variation was observed in energy charge of digestive gland from infected individuals and this was attributed to possible differences in the degree of infection.
Mol Biochem Parasitol 1984 Nov
PMID:The adenylate nucleotide pool in the digestive gland-gonad complex of Biomphalaria glabrata infected by Schistosoma mansoni. 652 94

Adenosine kinase, adenosine deaminase, hypoxanthine phosphoribosyltransferase, inosine-nucleoside phosphorylase, 5'-AMP deaminase and 5'-IMP nucleotidase were identified in cell-free extracts of duckling erythrocytes; no evidence for 5'-AMP nucleotidase and xanthine oxidase activity was found. The Km values for the duckling red cell enzymes were similar to those reported for human erythrocytes. Plasmodium lophurae extracts demonstrated similar enzyme activities except for 5'-AMP deaminase and 5'-IMP nucleotidase which were absent. It is proposed that during infection erythrocytic AMP is catabolized to IMP, inosine and hypoxanthine; the hypoxanthine is taken up by the plasmodium, utilized to form IMP, and this in turn is converted into adenine and guanine nucleotides.
Mol Biochem Parasitol 1981 Apr
PMID:Purine metabolizing enzymes of Plasmodium lophurae and its host cell, the duckling (Anas domesticus) erythrocyte. 678 22

The levels of ribonucleotides in the nematodes Haemonchus contortus, Ostertagia circumcincta, Trichostrongylus colubriformis, Nippostrongylus brasiliensis, Ascaris suum and Stephanurus dentatus, the cestode Moniezia expansa and the trematode Fasciola hepatica were measured by high pressure liquid chromatography. The adenylate charge, ATP and total adenine nucleotide levels were in general agreement with those determined enzymatically and with published data. UDP and guanine nucleotide levels were found to be higher than those present in mammals and previously reported for helminth parasites. Cytidine nucleotide levels varied considerably between parasite species. On the other hand inosine nucleotides were present at low concentrations in all species. Adenylate and guanylate charges were similar.
Mol Biochem Parasitol 1983 Jun
PMID:Ribonucleotide levels in six nematodes, a cestode and a trematode. 687 82

We examined Saccharomyces cerevisiae mitochondrial RNA for polyadenylate. Using hybridization to [3H]polyuridylate as the assay for adenylate sequences, we found adenylate-rich oligonucleotides approximately 8 residues long. Longer polyadenylate was not detected. Most of the adenylate-rich sequence is associated with the large mitochondrial rRNA. The remainder is associated with the 10-12S group of transcripts.
Mol Cell Biol 1982 Apr
PMID:Oligoadenylate is present in the mitochondrial RNA of Saccharomyces cerevisiae. 705 Jun 72

It is shown for beef pancreas tryptophanyl-tRNA synthetase that there exists a mechanism which provides additional discrimination in vitro after misactivation of monofluorinated tryptophan analogs. In the presence of tryptophan one can observe a rapid decomposition of noncognate aminoacyl adenylate-enzyme complexes containing 4-fluoro-, 6-fluoro- or 7-fluorotryptophan residues, whereas the stoichiometry aminoacyl adenylate.enzyme complexes with tryptophan and 4-fluorotryptophan residues is not changed. Rejection of noncognate aminoacyl adenylate-enzyme complexes is connected neither with the enzymatic hydrolysis of aminoacyl adenylate nor with the competition of non-cognate aminoacyl adenylate and the added amino acid for the enzyme binding site. Rejection of noncognate complexes is presumably caused by the interaction between the active centers localized on two subunits, with one of them being occupied by an amino acid molecule and the other one by noncognate aminoacyl adenylate.
Mol Biol (Mosk)
PMID:[Increasing specificity of tryptophanyl-tRNA synthetase after amino acid activation]. 707 Mar 77

Ultraviolet differential spectra (UDS) and CD-spectra of poly (A) in the presence of Cu2+ ions are studied at different degrees of phosphate groups screening. The binding of cu2+ ions with bases of phosphates is shown to lead to disordering or to ordering respectively, of the mutual orientation of nucleotides. The UDS components due to conformation variations in poly (A) and association between Cu2+ ions and its bases are calculated. Comparison of the latter UDS-component with the differential spectrum of a protonated adenosine-monophosphate permits to assume that Cu2+ ions are in a coordination bond with N (1) adenine. The calculation of the concentration dependence of the binding constants indicates binding cooperativity and weak dependence on the screening degree of poly (A) phosphate groups.
Mol Biol (Mosk)
PMID:[Effect of bivalent copper ions on conformation of polyriboadenylic acid]. 707 Mar 88

Hyperthyroidism induces a number of metabolic and physiological changes in the heart including hypertrophy, increase in inotropic status, and alterations of myocardial energy metabolism. The effects of hyperthyroidism on adenosine metabolism which is intimately involved in the control of many aspects of myocardial energetics, have not been clarified. The aim of this study was thus to evaluate the potential role of adenosine in the altered physiology of the hyperthyroid heart. Transport of adenosine was studied in cardiomyocytes isolated from hyperthyroid and euthyroid rats. Activities of different enzymes of purine metabolism were studied in heart homogenates and concentrations of nucleotide and creatine metabolites were determined in hearts freeze-clamped in situ. Both transport of adenosine into cardiomyocytes and the rate of intracellular phosphorylation were higher in the hyperthyroid rat. At 10 microM concentration, adenosine transport rates were 275 and 197 pmol/min/mg protein in hyperthyroid and euthyroid cardiomyocytes respectively whilst rates of adenosine phosphorylation were 250 and 180 pmol/min/mg prot. An even more pronounced difference was observed if values were expressed per number of cells due to cardiomyocyte enlargement. Hyperthyroidism was associated with a 20% increase in adenosine kinase, 30% decrease in membrane 5'-nucleotidase and 15% decrease in adenosine deaminase activities measured in heart homogenates. In addition there was a substantial depletion in the total creatine pool from 63.7 to 41.6 mumol/g dry wt, a small decrease in the adenylate pool (from 27.2 to 24.3 mumol/g dry wt) and an elevation of the guanylate pool (from 1.22 to 1.36). These results show that adenosine transport and phosphorylation capacity is enhanced in hyperthyroidism.(ABSTRACT TRUNCATED AT 250 WORDS)
Mol Cell Biochem 1995 Feb 23
PMID:Hyperthyroidism increases adenosine transport and metabolism in the rat heart. 759 49

The fluorescent probe 1,5-I-AEDANS was covalently attached to bovine tyrosyl-tRNA synthetase outside of enzyme active site in a nearly stoichiometric amount (2 probe molecules per enzyme dimer). Singlet-singlet resonance energy transfer has been used for the measurement of the apparent distance between tryptophan residues of enzyme and covalently attached 1,5-I-AEDANS. This distance was estimated as 27.4 A in the assumption of the random orientation of the donor and acceptor fluorophores. Tyrosyl adenylate formation catalyzed by bovine tyrosyl-tRNA synthetase resulted in the highly specific enhancement of 1,5-I-AEDANS fluorescence and concomitant decrease of the apparent distance between the probe and tryptophanyls to 22.3-25.7 A. These results are consistent with the conformational change of tyrosyl-tRNA synthetase during tyrosyl adenylate formation which propagates to distant from active site regions of enzyme structure.
Biochem Mol Biol Int 1995 Feb
PMID:Conformational change of mammalian tyrosyl-tRNA synthetase induced by tyrosyl adenylate formation. 766 86

It is well known that dopamine (DA) inhibits while vasoactive intestinal peptide (VIP) and angiotensin II (ANG II) stimulate prolactin (PRL) release from normal anterior pituitary lactotrophs; however, elucidation of the intracellular mechanisms involved in these effects has been hindered by the cellular heterogeneity of the anterior pituitary. MMQ cells, isolated from the PRL-secreting rat pituitary tumor 7315a is an interesting model since they only secrete PRL. In order to determine whether and which GTP-binding (G) proteins are involved in the modulation of cyclic 3',5'-adenosine monophosphate (cAMP) accumulation and phospholipids turnover and eventually PRL release, we have performed studies with MMQ cells. For this purpose, the levels of various G proteins (alpha o, alpha s, alpha i, alpha q and beta) and their mRNAs, measured by Western and Northern blots respectively, were correlated with intracellular cAMP accumulation in response to DA, VIP or DA plus VIP, and with inositol phosphates (IPx) formation in response to ANG II, DA or DA plus ANG II. This study shows that, when compared to normal pituitary tissue, the levels of alpha o, alpha o2 and alpha i3 were significantly decreased in MMQ cells; those of alpha o1, alpha i (alpha i1 + alpha i2), alpha s42 and alpha q were very low or undetectable while those of alpha s47 and beta were normal. DA was unable to inhibit basal PRL release and cAMP accumulation. VIP increased both cAMP accumulation and PRL release, while cAMP accumulation elicited by VIP could be suppressed by DA. BAY K 8644-induced PRL release also could be suppressed by DA.(ABSTRACT TRUNCATED AT 250 WORDS)
Mol Cell Endocrinol 1993 Jun
PMID:MMQ cells: a model for evaluating the role of G proteins in the modulation of prolactin release. 768 3


<< Previous 1 2 3 4 5 6 7 8 9 10